1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly to a technique which is effectively applicable to a liquid crystal display device with a narrow picture frame region.
2. Description of the Related Art
A liquid crystal display device has been used as display devices of various sizes used in applications ranging from a miniaturized mobile phone to a large-sized television receiver set.
FIG. 16 is a plan view for explaining a conventional liquid crystal display device. Here, a miniaturized liquid crystal display device is illustrated as one example. In the liquid crystal display device, a substrate SUB1 and a counter substrate SUB2 are adhered to each other using a sealing material SL, and liquid crystal is sandwiched between the substrate SUB1 and the counter substrate SUB2. An end portion of a side of the counter substrate SUB2 on a lower side of the drawing retracts from an end portion of a side of the substrate SUB1 on the lower side of the drawing, and a drive circuit DRV is mounted on the substrate SUB1 exposed by such retraction of the end portion. On a surface of the substrate SUB1 which is brought into contact with the liquid crystal, an orientation film ORI1 is formed by coating in a state that at least a display region AR is covered with the orientation film ORI1. In the same manner, on a surface of a counter substrate SUB2 which is brought into contact with the liquid crystal, an orientation film ORI2 not shown in the drawing is formed by coating in a state that at least the display region AR is covered with the orientation film ORI2.
Here, as a method for sealing liquid crystal, as shown in FIG. 16, there has been known a method in which a liquid crystal filling port is formed in a portion of the sealing material SL, the liquid crystal is filled in a space defined by the substrate SUB1, the counter substrate SUB2 and the sealing material SL through the liquid crystal filling port, and the liquid crystal filling port is sealed with a sealing material. As a method other than the above-mentioned method, there has been known a liquid crystal dropping sealing method in which, as described in patent document 1 (JP-A-11-38424) and patent document 2 (JP-A-2001-51282), for example, a sealing material SL is formed in an approximately closed rectangular shape without forming a liquid crystal filling port in the sealing material SL and, after dropping liquid crystal, a substrate SUB1 and a counter substrate SUB2 are adhered to each other to seal the liquid crystal. In this liquid crystal dropping sealing method, at the time of adhering the substrate SUB1 and the counter substrate SUB2, the liquid crystal spreads toward the sealing material SL and hence, in patent document 1 and patent document 2, for example, there is described a technique which forms a wall member in a region outside a display region AR and inside the surrounding sealing material SL thus suppressing spreading of the dropped liquid crystal.
Further, with respect to the sealing material SL, for example, patent document 3 (JP-A-2001-330837) describes a technique which forms an uneven surface on a portion which overlaps a sealing material SL for suppressing spreading of the sealing material SL when a substrate SUB1 and a counter substrate SUB2 are adhered to each other.